In this paper, the thermodynamic phase behaviour of pure and mixing nanoconfined fluids in shale reservoirs are studied. First, an analytical generalized equation of state (EOS) is developed by including the effects of pore radius and intermolecular interactions. Based on the generalized EOS, four extended cubic EOS are proposed and used to calculate the thermodynamic phase behaviour. The four extended cubic EOSs, the extended van der Waals (vdW), Redlich−Kwong (RK), Soave−Redlich−Kwong (SRK), and Peng−Robinson (PR) EOSs, are found to accurately predict the pressure–volume (P–V) diagrams of different systems in nanopores. More specifically, the extended RK (E-RK) EOS may fail to accurately calculate the phase behaviour at high temperatures and the extended PR (E-PR) EOS is more accurate for liquid phase pressure calculations. The overall calculated P–V diagrams for the pure components in nanopores from the extended EOS shift up and right relative to those of the bulk-phase case and the EOS only including the intermolecular interactions. Furthermore, as a physical meaningless phenomenon, the negative pressure state is completely avoided in the calculated P-V diagrams from the extended EOSs. Compared to the measured bubble-point pressure (Pb) for the four different confined mixing fluids, the E-vdW, E-RK, and E-SRK EOS provide accurate estimates of Pb with overall percentage average absolute deviations (AAD%) of 10.95%, 12.07%, and 9.37%, respectively. The proposed extended EOSs are capable to accurately predict the critical properties and their shifts in nanopores. A bottom limit for the continuous reduction of the critical properties by decreasing the pore radius is obtained from the proposed extended EOSs, which is, for example, 5 nm for C8H18.
On the basis of Nāgārjuna’s works, especially the Mūlamadhyamakakārikā, this paper proposes a sceptic presupposition as the departure point of Nāgārjuna’s refutations. This presupposition invalidates perceptual knowledge, and thus the identities of existents (svabhāva) can only be deemed as referents assumed by concepts (nāman, vikalpa, etc.). Then the “confinement principle,” a theorem tacitly applied in Nāgārjuna’s arguments, is justified, i.e., any definition or description of a concept would necessarily confine its assumed referent to an invariable and isolated state. This principle enables Nāgārjuna to deduce contradictions between the static and isolated nature of the assumed referent, and the activity in which it must be involved. Notions of both a static identity and its activity are deep-rooted in all referential mental activities of sentient beings. Hence all concepts are found to be self-contradictory and therefore devoid of referents (niḥsvabhāva), namely, empty (śūnya). Thus, Nāgārjuna is refuting the whole intelligible world, and his position can be identified as epistemological nihilism—nothing within our ken can possibly be
Huang Y, Bu Y, Ding Y, Lu W. From zero to one: A citing perspective. Journal of the Association for Information Science and Technology. 2019;70(10):1098-1107.
Confined fluids undergo substantial changes in terms of their physicochemical properties when the pore radius reduces to the nanometric scale and be comparable to the molecular size. Adsorptions, which are the corresponding changes in the concentration of a given fluid at the interface compared with the other contacting phase, strongly affect the vapour-liquid equilibrium (VLE), especially in nanopores. No published literature so far has been found to study the critical shifts of confined fluids with adsorptions in nanopores. In this study, first, the van der Waals (vdW) and Soave-Redlich-Kwong (SRK) equations of state (EOSs) are extended to calculate the VLE of confined fluids in nanopores. Second, a new empirical correlation is developed to calculate the fluid adsorption thickness in nanopores. Finally, two generalized analytical formulations, on a basis of the modified vdW and SRK EOSs, are initially proposed to calculate the shifts of critical temperatures and pressures by considering the fluid adsorptions in nanopores. All the extended EOSs, new adsorption correlation, and two generalized formulations have been validated to be accurate by comparing with the experimental or literature data. Overall, the critical properties of the confined fluids are found to shift more with adsorptions in nanopores. Moreover, the compressibility factors of the confined Lennard–Jones fluids are proven to be universal and independent of the pore radius effect.
To reduce the burden of storing and transmitting audio signals, they are often compressed with a lossy single-channel code. Because the high-frequency components are effectively truncated when using a low bitrate encoder, listeners may experience the sound as being uncomfortable, muffled, or dull. To compensate for the perceived degradation, bandwidth extension technology can be used to regenerate the missing high frequencies from the low-frequency components during the decoding process. In this paper the authors propose a bandwidth extension method based on Generative Adversarial Networks (GAN), which is used to estimate the relationship between the MDCT spectrum in the high-frequency part and the low-frequency part. It is evaluated by a discriminant network in the GAN to get a more natural result. A complete audio coding system was built by using AAC Low Complex as the single-channel core encoder with the proposed bandwidth extension method. To evaluate the audio quality decoded by the new system, a subjective evaluation experiment was carried out using the HE-AAC as the baseline system with the MUSHRA experimental method.
While short-chain chlorinated paraffins (SCCPs) comprise a myriad of components whose physicochemical properties are extremely diverse, many previous studies characterized the SCCP mixtures collectively using a single set of physicochemical properties when modeling the global environmental fate and risk. In this work, we explore whether a discrepancy exists between simulations based on a single set of physicochemical properties and multiple component-specific ones in global fate and risk modeling, and the environmental condition (e.g., proximity to emission source vs. temperature) in which such a discrepancy is most notable. We simulated the environmental concentrations and compartmental distribution of SCCPs, using a mechanistic fugacity-based multimedia BETR-Global model. We observed a discrepancy between modeled concentrations based on a single and multiple sets of properties, which is more notable in regions with a low temperature and negligible emissions, e.g., the remote and cold background Arctic region. The modeled compartmental distribution differs slightly between simulations based on different sets of physicochemical properties. While using a single set of properties minimizes input data required for model-based evaluation of the risk of SCCPs, it tends to underestimate the environmental occurrence and risk in remote and cold regions, which are vulnerable and hence deserve a more conservative evaluation conclusion, and prevents us from drawing conclusions on which SCCP component is of greatest concern. The current work can be a relevant step towards improving the methodology for global environmental modeling and risk assessment of SCCPs and other complex halogenated chemical mixtures.